Flexible orthotic device

ABSTRACT

An orthotic device which provides functional support for the foot. It comprises a substantially rigid moulded sheet of resiliently deformable plastics material which provides continuous contact with the arch of the foot whether the foot is flat or pointed. The plastics material is preferably embedded between a shock absorbent layer and a covering layer.

BACKGROUND OF THE INVENTION

[0001] This invention relates to orthotic devices and is particularlyconcerned with resiliently flexible orthotic devices which are designedto provide functional support for the foot without inhibiting thefunctional motion of the foot.

[0002] The invention will primarily be described in relation to insertsfor footwear, particularly performance footwear such as dancing, balletand athletic shoes, however it also extends to orthotic devices whichare fitted directly to the foot or indirectly with the use of some formof containment such as hosiery, bandages, strapping or layeredmaterials. These broader aspects of the invention should therefore beborne in mind and the following description of preferred embodimentsshould not be deemed to be any way limiting on the scope of theinvention.

[0003] When it comes to providing functional assistance and comfort tothe foot, dancers have always been at a disadvantage. This is due mainlyto the restrictive accommodation of dancing footwear as exemplified byballet slippers. Any insole with support or support padding limits therange of foot function (flat foot position to en pointe) and also causesthe slipper to bulge out, especially at the inner side of the foot.These types of insoles are not functionally or aesthetically acceptable.

[0004] Dancers and other athletes who perform high impact and repetitiveactivities with their feet often develop soft tissue and bone pathologyin the foot and leg. This situation is compounded when supportive andcushioned footwear cannot be worn during these activities. Dancers whowear ballet slippers are particularly at risk and suffer a number ofpainful conditions ranging from aches, cramps and tendonitis to stressfractures or complete fracture of the bones in the feet. Gymnasts,boxers and sprinters have similar problems.

[0005] A “high arched” foot is of paramount importance for a balletdancer. When the foot is maximally arched, the bones of the foot arelocked together and the foot is rigid. This rigidity provides thestability necessary to maintain an “en pointe” (or tiptoe) dancingposition. This position also necessitates strengthening and maintainingthe strength of the muscles both in the leg and the foot. Dancers arenot permitted to dance “en pointe” until the foot and the leg musclesare strong enough to ensure stability, control and safe dancing in thisposition. The “arched” foot look is also considered aestheticallypleasing and all dancers strive to enhance the “look” of the foot.

[0006] In many sporting endeavours, and certainly in classical dance,the foot has little protection from the performing surface, or therepetitive nature of the activity being undertaken in training andperformance. In “normal” foot function, the bones of the foot will moveslightly from a locked position to an unlocked position depending on thefunction of the muscles. These changes allow the “shock” forces from theground to be dissipated via the soft, tissues within the foot when thefoot is unlocked, and for control and stability to be achieved when thefoot is locked. When the muscles which control these movements are weakor used inappropriately the foot cannot sustain good function. Poor footstructure also results in poor foot function.

[0007] This invention was inspired out of the necessity to treat dancersand other athletes who had developed serious injuries due to thecombination of unprotected repetitive activity and poor “sustained” footfunction—often due to muscle fatigue.

OBJECT OF THE INVENTION

[0008] It is therefore an object of the invention to provide an orthoticdevice which will enhance the arch profile and performance of the foot,particularly in restrictive performance footwear.

[0009] It is a further object of the invention to provide protection tothe foot from abnormal impact forces.

SUMMARY OF THE INVENTION

[0010] According to the broadest aspect of the present invention thereis provided an orthotic device which comprises a substantially rigidmoulded sheet of resiliently deformable plastics material which providescontinuous contact with the arch of the foot whether the foot is flat orpointed, after it has initially been moulded to substantially conformwith the shape of the arch of the foot.

DETAILED DESCRIPTION OF THE INVENTION

[0011] The orthotic device is formed from a plastics material which ismoulded by heat, microwaves or other appropriate means to produce a higharch profile. The plastics material is chosen from the range of plasticshaving a shape “memory” property which permits it to be flattened outunder applied pressure and then to return to its original memorizedconfiguration once the applied pressure has been removed. The sheetplastics material should also be such as to provide a firm yet flexiblecontact with the arch of the foot. The sheet will suitably range inthickness from less than one millimetre to a few millimetres, preferablyapproximately one millimetre, and may comprise several sheets laminatedtogether.

[0012] The ability of the resiliently flexible orthotic device to bemoulded enables it to be shaped or reshaped to the arch contours of theparticular foot it is to be used with by a simple process such as directheating using a hair dryer or the like or by placing it in a microwaveoven. When the device is heated or microwaved, it softens sufficientlyto enable shaping. As it hardens, it memorises the shape into which ithas been formed.

[0013] Although there are a large number of known plastics materialswhich exhibit the above properties and which would be suitable forforming the flexible orthotic device according to the invention, thepreferred plastics material is the product sold under the trade nameQuikform™ by Acor Orthopaedic, Inc. of the U.S.A. This product has amoulding temperature of around 200° F.

[0014] The function of the resiliently flexible orthotic device isthreefold, viz:

[0015] (1) to stimulate the arch and the superficial muscles under thefoot,

[0016] (2) to remind the wearer to “pull up the arch” using the musclesof the leg and foot, and

[0017] (3) to engender confidence in the wearer by providing a sensationof support under the arch of the foot.

[0018] The orthotic device can be made to fit the template of theperformance footwear it is to be used with and suitably includes aportion which enables it to be secured to the heel portion of thefootwear. For instance, the orthotic device can be secured with a twoway thin adhesive wafer or a thicker velcro® dot to enable transferbetween footwear. In addition, the orthotic device could be strappeddirectly to the foot or retained within a suitable stocking.

[0019] In another aspect of the invention, there is provided amulti-layered orthotic device. This device comprises the mouldable sheetof plastics material referred to hereinbefore, sandwiched between ashock absorbent layer and a covering layer. The covering layer isintended to lie adjacent the foot of the wearer and the shock absorbentlayer is intended to face the sole of the wearer's shoe.

[0020] The shock absorbent layer and the covering layer may alsocomprise multi layers of the same or different material to increaseshock absorbency if required or to provide additional stimulus orcomfort to the arch.

[0021] The shock absorbent or base, layer can be manufactured from anyconventional shoe insert material commonly used for this purpose.Typical examples of these materials are foamed plastics and rubbermaterials such as polyurethanes and polyisoprenes. Particularlypreferred are the Poron® Medical Cellular Urethanes. These areengineered, high density, microcellular urethane foam materialsdesigned. for use in orthotic and prosthetic applications. Poron®medical materials are mechanically foamed, resulting in excellentthickness tolerance and lot to lot consistency. They will not thin outor take a compression set, and will retain 95% of their originalthickness for the life of the product. These materials are excellentshock absorbers. Each of the cells in the material acts like a tinyspring or energy absorber. Coupled with the compression set properties,these materials will not lose their ability to absorb shock over time.

[0022] The preferred Poron® layer used is a split material with aroughened surface, which is laminated to the rest of the other layers,and a smooth surface. The smooth surface contacts the insole of thefootwear, which allows the orthotic device to coil and recoil withminimal friction.

[0023] Poron® materials are easily cut and fabricated and can be adheredor laminated to a wide range of other materials. Gram for gram, thismaterial is a superior shock absorber and this lightweight quality makesit suitable for use in the invention.

[0024] The covering, or top, layer of the orthotic device is selectedfrom a range of materials having one or more of the followingproperties:

[0025] protects the skin of the plantar surface of the foot,

[0026] resists moisture retention,

[0027] has suitable formability to be able to withstand the coil andrecoil movement of the orthotic device,

[0028] withstands repetitive use,

[0029] increases comfort under the arch of the foot,

[0030] is hypoallergenic,

[0031] increases the stimulus under the arch.

[0032] The preferred covering is leather. Other covers specificallydesigned for sweaty feet, skin disorders and increased tactile stimulusmay also be used.

[0033] The three layers of the orthotic device are preferably adheredtogether with a commercial adhesive which is commonly used in thefootwear industry. A particularly preferred adhesive is sold under thetrade name Duall 88®.

[0034] The last size and shape of the footwear will determine thedimensional parameters of the multi-layered orthotic device. Body weightand the intended activity will determine the thickness of the shockabsorbent layer and the covering layer.

[0035] The shock absorbent layer is suitably cut to the dimensions ofthe full last of the footwear.

[0036] The inner sheet of plastics material is limited in width to thewidth of the last and limited in length to the length of the innerlongitudinal arch. (This dimension is calculated on the length of thelast). This layer is therefore significantly shorter at both ends thanthe shock absorbent layer and the covering layer.

[0037] The outer covering layer is cut either to the actual dimensionsof the last (as with the shock absorbent layer) or 1 mm larger to enableextra shock absorbency to be added at any time if required.

[0038] The flexible characteristic (coil and recoil) of the orthoticdevice according to the present invention is unique and sets it apartfrom other insole devices. Other insole devices are designed to supplyshock absorbency, to carry a medicament (eg. Charcoal odour eaterswithin the insole), to restrict foot function or to support the bones ofthe foot. The present orthotic device provides constant contact with thearch, stimulating the skin, nerve endings and the superficial musclesunder the foot.

[0039] The flexibly resilient orthotic device is not an arch support asit is designed to allow the foot to be flexible and the characteristicsof the device do not provide any extrinsic support to the footwhatsoever.

[0040] The orthotic device will be available as an “off the shelf”purchase, and will be packaged according to the size of the performancefootwear. It will preferably be distributed in flat form, with clearinstructions and simple diagrams explaining the moulding process.

BRIEF DESCRIPTION OF THE DRAWINGS

[0041]FIG. 1 is a side cross-sectional view of an orthotic device in anextended configuration,

[0042]FIG. 2 is a top plan view of the orthotic device show in FIG. 1;

[0043]FIG. 3 is a partial top perspective of the orthotic device shownin FIGS. 1 and 2, in an arched configuration;

[0044]FIG. 4 is a cross-sectional view of the orthotic device shown inthe previous Figures in situ, with in a ballet shoe, and

[0045]FIG. 5 is a cross-sectional view of the orthotic device and balletshoe shown in FIG. 4 in an “en pointe” configuration.

DESCRIPTION OF PREFERRED EMBODIMENT

[0046] A preferred embodiment of the invention will now be describedwith reference to the accompanying drawings, in all of which likereference numerals refer to like parts.

[0047]FIGS. 1 and 2 show a multi-layered flexible orthotic device in aform in which it would be purchased or in a form it would assume under aflat foot in performance footwear.

[0048] The orthotic device comprises a shock absorbent layer 10, amouldable sheet of plastics material 11 and a covering layer 12.

[0049] The shock absorbent layer 10 consists of a 1 mm layer of Poron®,as referred to hereinbefore; the mouldable sheet of plastics material 11consists of a 1 mm thick insert fabricated from Quickform™ positioned inthe arch region only of the orthotic device; and the covering layer 12consists of a 1 mm thick layer of leather. All layers are adheredtogether with the adhesive Duall 88®, also previously referred to.

[0050] As noted, FIGS. 1 and 2 illustrate the form the orthotic devicetakes when it is purchased. Accordingly, in order to transform it into auseable product with a memorized arch configuration as shown in FIG. 3,the orthotic device must be subjected to radiant heat or microwaveradiation of a sufficient intensity to enable the sheet of plasticsmaterial to become mouldable, without adversely affecting the integrityof the covering and the shock absorbent layers. One preferred method toachieve this utilizes a hair dryer on high heat. The hair dryer is heldapproximately 20 cm away from the orthotic device and hot air isdirected at the outer surface of the shock absorbent layer 10. Heat isnot applied to the covering layer 12. The nozzle of the hair dryer ismoved up and down to direct an even flow of hot air to the mouldablesheet of plastics material 11. The plastics material typically softensafter a few minutes of such treatment. The orthotic device is then bentin half so that the undersides face each other, and is rolled to and frobetween the hands several times. It is placed topside facing upwards ona flat surface and the central portion is bent into an exaggerated archby pushing the toe end and the heel end towards each other until theyare approximately 2 cms apart. This shape is maintained until theorthotic device cools. When completely cool, the orthotic device isplaced in the footwear. If required, securement can be achieved using avelcro® fixing or the like under the heel.

[0051] As weightbearing occurs on the arch, the flexible resilientorthotic device will slide forward and flatten as shown in FIG. 4 thenrecoil when the heel is lifted or weight is transferred to the lateralborder of the foot as shown in FIG. 5. The orthotic device will ensurecontact with the arch at all times.

[0052] Should the orthotic device lose its arch shape over a period oftime due to excessive and continued use, it can simply be reheated asabove to reestablish the required arch shape.

[0053] Whilst the above has been given by way of illustrative example ofthe invention, many modifications and variations may be made thereto bypersons skilled in the art without departing from the broad scope andambit of the invention as herein set forth.

1. An orthotic device which comprises a substantially rigid mouldedsheet of resiliently deformable plastics material which providescontinuous contact with the arch of the foot whether the foot is flat orpointed, after it has initially been moulded to substantially conformwith the shape of the arch of the foot, wherein said orthotic devicedoes not provide support for the arch of the foot.
 2. An orthotic deviceas claimed in claim 1, wherein the plastics material has a shape memoryproperty which permits it to be flattened out under applied pressure andto return to its original memorized arched configuration once theapplied pressure has been removed.
 3. An orthotic device as claimed inclaim 1, which is designed to fit the template of the footwear it is tobe used with.
 4. An orthotic device as claimed in claim 1, and includinga shock absorbent layer and a covering layer, wherein the covering layeris intended to be adjacent to the bottom of the foot, the absorbentlayer is intended to face the sole of the footwear, and the orthoticdevice is sandwiched between the layers.
 5. An orthotic device asclaimed in claim 4, wherein there are multiple shock absorbent layers.6. An orthotic device as claimed in claim 4, wherein there are multiplecovering layers.
 7. An orthotic device as claimed in claim 4, which onlyextends to the arch region of the foot.
 8. An orthotic device as claimedin claim 4, which extends the entire length of the foot.
 9. An orthoticdevice as claimed in claim 4, wherein the shock absorbent layer is afoamed plastics material.
 10. An orthotic device as claimed in claim 9,wherein the foamed plastic material is a microcellular urethane foamedmaterial.
 11. An orthotic device as claimed in claim 10, wherein thelayer of microcellular urethane foamed material has a smooth outersurface which contacts the footwear and a roughened inner surface whichconnectively joins with the orthotic device.
 12. An orthotic device asclaimed in claim 4, which is laminated to the shock absorbent layer andthe covering layer.
 13. An orthotic device as claimed in claim 4, whichis adhered to the shock absorbent layer and the covering layer.
 14. Anorthotic device as claimed in claim 4, wherein the covering layer isleather.
 15. An orthotic device as claimed in claim 4, wherein the shockabsorbent layer is dimensioned to match the full last of the footwear.16. An orthotic device as claimed in claim 4, which has the same widthas the last of the footwear and has a length which is commensurate withthe length of the inner longitudinal arch of the foot.
 17. An orthoticdevice as claimed in claim 4, wherein the covering later is dimensionedto match the dimensions of the last of the footwear.
 18. An orthoticdevice substantially as herein described with reference to theaccompanying drawings.